These octal bus transceivers are designed for asynchronous two-way communication between data buses. The control-function implementation allows for maximum flexibility in timing.

These devices allow data transmission from the A bus to the B bus or from the B bus to the A bus, depending upon the logic levels at the output-enable (OEAB and ) inputs.

The output-enable inputs disable the device so that the buses are effectively isolated. The dual-enable configuration gives the transceivers the capability to store data by simultaneously enabling OEAB and . Each output reinforces its input in this transceiver configuration. When both OEAB and are enabled and all other data sources to the two sets of bus lines are in the high-impedance state, both sets of bus lines (16 total) remain at their last states. The 8-bit codes appearing on the two sets of buses are identical for the SN74ALS621A, SN74ALS623A, and SN74AS623 or complementary for the SN74ALS620A.

The -1 versions of the SN74ALS620A and SN74ALS621A are identical to the standard versions, except that the recommended maximum I_OL is increased to 48 mA in the -1 versions.

The SN74ALS620A, SN74ALS621A, SN74ALS623A, and SN74AS623 are characterized for operation from 0°C to 70°C.

• Local Bus-Latch Capability
• Choice of True or Inverting Logic
• Package Options Include Plastic Small-Outline (DW) Packages and Standard Plastic (N) 300-mil DIPs

• IOL (Max) (mA)
• 24
• IOH (Max) (mA)
• -15
• Technology Family
• ALS
• Rating
• Catalog
• Operating temperature range (C)
• 0 to 70

SN74ALS621A的完整型号有：SN74ALS621ADW、SN74ALS621AN，以下是这些产品的关键参数及官网采购报价：

SN74ALS621ADW，工作温度：0 to 70，封装：SOIC (DW)-20，包装数量MPQ：25个，MSL 等级/回流焊峰值温度：Level-1-260C-UNLIM，引脚镀层/焊球材料：NIPDAU，TI官网SN74ALS621ADW的批量USD价格：2.229（1000+）

SN74ALS621AN，工作温度：0 to 70，封装：PDIP (N)-20，包装数量MPQ：20个，MSL 等级/回流焊峰值温度：N/A for Pkg Type，引脚镀层/焊球材料：NIPDAU，TI官网SN74ALS621AN的批量USD价格：2.563（1000+）

14-24-LOGIC-EVM — 支持 14 到 24 引脚 PW、DB、D、DW、NS、DYY 和 DGV 封装的通用逻辑 EVM

该 EVM 设计用于支持采用 14 至 24 引脚 D、DW、DB、NS、PW、DYY 或 DGV 封装的任何逻辑器件。